Hi Doubs!
[quote]Originally posted by Doubs:
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With the striker in the cocked position - as it would be for firing - the force of the firing pin spring is actually pushing back against the breechblock </strong><hr></blockquote>
Yes sir, the net effect is as if the striker spring were directly acting against the breechblock. But in reality the striker spring is actually not pressing directly against the breechblock. Rather it is pressing forward against the inside front surface of the striker channel in the striker, and rearwards against the breechblock end piece, which in turn is pressing rearward against the breechblock.
[quote]Originally posted by Doubs:
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and it takes VERY LITTLE momentum to cause the toggles to pop up.
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Quite right! But whatâ??s happening here is actually quite complicated.
With the striker held at the cocked position the pressure exerted by the striker spring is bi-directional. It is exerting pressure forward against the striker, and rearward against the breechblock (via the breechblock end piece). So long as the toggle pivot point is below the centerline of the toggle train this rearward striker spring pressure on the breechblock serves to retard upward motion of the toggle knobs. But as soon as the toggle knobs have been raised enough to bring the toggle pivot point above the centerline of the toggle train and the rigidity of the toggle train is broken, then the compressed striker spring will fling backwards the breechblock, causing the toggle knobs to jump upwards.
[quote]Originally posted by Doubs:
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The striker spring pressure actually HELPS to push the toggles up. </strong><hr></blockquote>
Yes sir, it does, but only after toggle pivot point is above the centerline of the toggle train. Conversely, the striker spring opposes forward movement of the toggle train once the teat on the striker contacts the sear and the striker spring begins to be compressed between the inside front surface of the striker channel in the striker and the breechblock end piece.
[quote]Originally posted by Doubs:
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(In fact, the striker spring does more to keep the train locked when it's NOT cocked as the train has to overcome the drag of the sear and the striker spring pressure to reach the "toggles broken" point.) </strong><hr></blockquote>
Here I have to respectfully and cordially disagree. When the striker in not cocked, it is forward of the sear and there is no sear drag - as there is no contact with the sear. Also, the striker spring is not compressed by the rearward movement of the toggle train. Rather it is compressed by the forward movement of the toggle train after the teat on the striker contacts and is held to the rear by the sear - an uncompressed striker spring provides no spring pressure.
That said the striker, during rearward movement of the toggle train, must pass by the rear of the sear and to do so must push the rear outward. This outward motion of the rear of the sear is resisted by the sear spring, so the inward pressure on the rear of the sear exerted by the sear spring must be overcome by the force being used to draw the breechblock (and the striker it contains) to the rear. Thus the rearward motion of the toggle train is not inhibited by either the striker spring or sear drag, but rather by the sear spring which opposes the movement of the outward movement of the sear to clear the path of the striker as the strike moves to the rear.
[quote]Originally posted by Doubs:
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Turn the cannon over and tap the top of the receiver where the date is normally stamped against the ball of your palm. If the pistol had been designed for zero main spring tension on the toggle train when in battery and with only the striker spring pushing back on the train, the design would never have flown and it would be a long forgotten footnote in the history of firearms.
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This is true, and I donâ??t think anyone has suggested otherwise.
The point I was making (and this seemed to gotten lost in the discussion fairly quickly {wry smile}) is that the pressure of the main spring pushing the toggle train forward during firing becomes equal to or less than the pressure of the striker spring as the striker spring resists compression during forward movement of the toggle train during firing. At this point in time during action cycling the force acting to bring the toggle train forward is only the momentum of the toggle train, imparted to the toggle train by the main spring before the main spring force was equaled or overcome by the resistance of the striker spring.
[quote]Originally posted by Doubs:
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There is NO POINT in the cycling of the action from cocked and locked through opening, ejection and chambering a new round that does not have main spring pressure applied to the train. Even with the striker uncocked, there is main spring pressure being applied. It's part of the design. If that wasn't true, there wouldn't be pressure of varying weight applied to the train at ALL times by the main </strong><hr></blockquote>
Again, quite true and not something Iâ??ve ever disputed. Mainspring pressure on the toggle train exists throughout the movement of the toggle train. But this mainspring pressure is countered by, and becomes mechanically insignificant, when the toggle train returns forward sufficiently for the striker spring to resist the forward movement of the toggle train.
Warmest regards,
Kyrie
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